Apparatus and method for lubricating and cooling in a draw and iron press

Abstract

The invention includes apparatus and method for lubricating and cooling a workpiece, dies or ironing rings, and punch at the interface between the workpiece and such dies or ironing rings and punch in forming a workpiece into a hollow closed end cylindrical article. A lubricant liquid phase is injected into a coolant liquid phase to form a "dispersion" prior to application to the metal-tool interface. Providing the lubricant as a dispersion in the coolant liquid phase rather than as an emulsion provides several advantages. The quantity of lubricant and the time of lubricant injection can be varied to control lubricity and, thus, friction. The invention makes it possible to achieve differential friction in the ironing process by having higher lubricity on the ironing die (low friction) and lower lubricity on the punch surface (high friction). Lubricities and cooling are controllable for the specific metal forming process employed to produce closed end hollow body containers. After applicaiton, the lubricant and coolant are separated, the lubricant filtered to remove debris, stored, and then reinjected to provide lubrication for the process.

What is claimed is: 
     
       1. Apparatus for drawing and ironing aluminum to make a closed end hollow aluminum body of acceptable surface quality comprising: (a) at least one ironing ring;   (b) a punch adapted for reciprocal motion in coaxial alignment with said ironing ring to drawn and iron an aluminum workpiece through said ironing ring to form a closed end hollow aluminum body;   (c) a lubricating and cooling ring adjacent said ironing ring provided with channels for receiving, circulating, and discharging a lubricant or a coolant into the ring at an interior location, respectively, to lubricate or cool the ironing ring and said workpiece being forced therethrough;   (d) a coolant supply line leading to said lubricating and cooling ring;   (e) means for mechanically dispersing lubricant in coolant to make a lubricant dispersion;   (f) a lubricant dispersion supply line leading to said lubricating and cooling ring; and   (g) means for injecting said coolant through said coolant supply line to said lubricating and cooling ring controllably intermittently with said lubricant dispersion through said lubricant dispersion supply line to said lubricating and cooling ring to form a uniform application of lubricant dispersion on said aluminum body and to vary lubricity at selected times during a working cycle of drawing and ironing.   
     
     
       2. Apparatus as set forth in claim 1 wherein said means for injecting said coolant controllably intermittently with said lubricant dispersion has at least one receiving channel ring inlet to the lubricating and cooling ring from the lubricant dispersion supply line and a plurality of said circulating channel passageways of substantially equal length extending from said lubricant dispersion supply line to a plurality of discharging channel ring outlets spaced angularly apart around the interior of the ring to form said uniform application of lubricant dispersion on said aluminum body. 
     
     
       3. Apparatus as set forth in claim 1 wherein said means for injecting said coolant controllably intermittently with said lubricant comprises first annular manifold means for applying said coolant and second annular manifold means for applying said lubricant dispersion, each annular manifold means having a ring inlet and independent spaced channels extending from the manifold to one or more ring outlets in the interior of the ring. 
     
     
       4. Apparatus as set forth in claim 1 wherein the means for mechanically dispersing lubricant comprises an injection nozzle in said dispersion supply line located upstream from the cooling ring. 
     
     
       5. Apparatus as set forth in claim 1 which includes means for controlling supply of lubricant dispersion to said closed end hollow aluminum body to form said uniform application in accordance with movement of the punch, such that more lubricant is fed during forward stroke than on return stroke. 
     
     
       6. Apparatus as set forth in claim 5 comprising two or more ironing rings disposed to contact said workpiece only one said ironing ring at a time and a reservoir for coolant and a reservoir for lubricant. 
     
     
       7. Apparatus as set forth in claim 6 which includes means for collecting and filtering the lubricant dispersion after it has lubricated and cooled the ring and means for separating the lubricant from the coolant after filtering the dispersion, means for transporting the filtered lubricant to a lubricant reservoir, and means for transporting the filtered coolant to a coolant reservoir. 
     
     
       8. Apparatus as set forth in claim 7 wherein the means for controlling the supply of lubricant includes a means for detecting the location of the punch with reference to the lubricating and cooling ring as the punch moves reciprocally, a valve for allowing or stopping the flow of lubricant to the nozzle, a means for operating the valve, and means for sending signals from the punch detecting means to the valve operating means to operate the valve according to such signal. 
     
     
       9. A method of lubricating and cooling an ironing die, punch, and aluminum workpiece to form a closed end hollow aluminum body in a draw and iron press comprising: (a) dispersing a lubricant in a coolant to make a dispersion; and   (b) during drawing and ironing of said aluminum workpiece contacting the die, punch, and aluminum workpiece with the dispersion controllably intermittently with additional coolant in a manner to form a uniform application of dispersion on said aluminum workpiece and to vary lubricity at selected times during a working cycle of drawing and ironing.   
     
     
       10. A method as set forth in claim 9 wherein said dispersing comprises mechanically injecting said lubricant in said coolant to form a dispersion of unstable liquid phase. 
     
     
       11. A method as set forth in claim 10 further comprising: (c) separating said unstable liquid phases to form lubricant substantially free of said coolant.   
     
     
       12. A method as set forth in claim 11 wherein said dispersing includes injecting variable amounts of lubricant into coolant. 
     
     
       13. A method as set forth in claim 12 further comprising controlling said injecting at different times or lubricant amounts to provide a friction between a workpiece and ironing die lower than a friction between the workpiece and punch surface. 
     
     
       14. A method as set forth in claim 13 further comprising controlling said injecting at predetermined intervals to discharge the dispersion into a lubricating and cooling ring interior at a predetermined time. 
     
     
       15. A method as set forth in claim 14 whereby the predetermined time when the dispersion is discharged into the lubricating and cooling ring interior is from the time of entry of the workpiece into the interior of the lubricant ring until exit of the workpiece therefrom. 
     
     
       16. A method as set forth in claim 14 whereby contacting with the dispersion controllably intermittently with said additional coolant to form a uniform application of dispersion on said aluminum workpiece comprises passing said dispersion through a hollow cylindrical lubricating and cooling ring having an annular manifold therein and an inlet thereto for receiving said dispersion from a dispersion supply lie and further comprises discharging the dispersion into the lubricating ring interior through spaced apart passageways leading from the manifold. 
     
     
       17. A method as set forth in claim 16 whereby the lubricating ring includes a second annular manifold independent from the first annular manifold having independent passageways to the lubricating ring interior and the method includes receiving a liquid which is substantially coolant in such second manifold and discharging it through the passageways into the lubricating ring interior. 
     
     
       18. A method as set forth in claim 16 whereby the manifold is divided into channels of substantially equal length from the supply line inlet to spaced apart points of discharge in the ring interior and the method includes distributing the received dispersion in such channels such that each dispersion is uniformly discharged around the ring interior. 
     
     
       19. A method as set forth in claim 18 which includes dispersing the lubricant in an amount sufficient to make a dispersion having a dispersed lubricant content by volume of 0.2% to 0.6% at droplet sizes in the range of 40-50 microns in diameter. 
     
     
       20. A method of lubricating and cooling an ironing die, punch, and workpiece in a draw and iron press comprising: (a) dispersing a lubricant of mineral oil or synthetic oil by injecting said lubricant into a coolant of water to form an unstable mechanical dispersion of lubricant-coolant in at least two lubricating streams;   (b) controlling the lubricant content in said lubricant-coolant to provide variable lubricities in the different lubricating streams;   (c) applying a first injected lubricating stream to said ironing die and workpiece on the forward stroke;   (d) applying a second lubricating stream to said punch on the return stroke such that said first lubricating stream provides a surface friction lower than said second stream; and   (e) collecting lubricant from said first and second streams in a common lubricant reservoir substantially free from said coolant.